1. Field of the Invention:
The present invention relates to an image display apparatus for displaying a three-dimensional image on a display and providing a stereoscopic image through liquid crystal shuttered spectacles, shutters of which are controlled to obtain the stereoscopic image.
2. Description of the Related Art:
FIG. 1 is a perspective view showing construction of a conventional image display apparatus for example as disclosed in Japanese Laid-open Patent Publication No. 62-61493. Referring to the figure, reference numeral 1 denotes a three-dimensional image generation unit for outputting images for the right eye and for the left eye, 9 denotes a display unit connected with the three-dimensional image generation unit 1 by a video signal line 10 and a synchronizing signal line 11 for displaying an image from the three-dimensional image generation unit 1, and 6 denotes an infrared ray transmitting device for transmitting a shutter control signal, sent over from the three-dimensional image generation unit 1 through a shutter control signal line 12, to a liquid crystal shuttered spectacle device 13 in the form of an infrared ray.
FIG. 2 is a block diagram showing a detailed structure of the apparatus shown in FIG. 1. As shown in FIG. 2, the three-dimensional image generation unit 1 has a three-dimensional image signal generator 2 for generating image signals for the right eye and the left eye, a RGB video signal output circuit 3 accepting an image signal from the three-dimensional image signal generator 2 for generating an RGB video signal, a synchronizing signal generator 4 accepting an image signal from the three-dimensional image signal generator 2 for generating a synchronization signal, and a shutter control signal generator 5 accepting a signal from the three-dimensional image signal generator 2 for generating a shutter control signal.
The liquid crystal shuttered spectacle device 13 is formed of a liquid crystal shutter control device 7 and liquid crystal shuttered spectacles 8. The liquid crystal shuttered spectacles 8 have a liquid crystal shutter for the right eye and a liquid crystal shutter for the left eye. The liquid crystal shutter for the right eye and the liquid crystal shutter for the left eye are controlled to open and shut by the liquid crystal shutter control device 7 respectively.
In the image display apparatus of the described arrangement, the three-dimensional image signal generator 2 alternately generates an image for the right eye and an image for the left eye. The RGB video signal output circuit 3 alternately outputs a RGB video signal for the right eye and a RGB video signal for the left eye. Also the synchronizing signal generator 4 alternately outputs a synchronizing signal for the right eye and a synchronizing signal for the left eye. Accordingly, the display unit 9 alternately displays an image for the right eye and an image for the left eye. The shutter control signal generator 5 generates a shutter control signal synchronized with the display on the display unit 9. More specifically, the shutter control signal is a signal causing the liquid crystal shutter for the right eye to be opened when the image for the right eye is displayed on the display unit 9 and the liquid crystal shutter for the left eye to be opened when the image for the left eye is displayed on the display unit 9.
The shutter control signal is input to the infrared transmitting device 6. The infrared ray transmitting device 6 emits the input shutter control signal in the form of an infrared ray. The liquid crystal shutter control device 7 has an infrared ray receiving portion. The infrared ray receiving portion receives the shutter control signal in the form of an infrared ray and the liquid crystal shutter control device 7, responding to the shutter control signal, alternately opens the liquid crystal shutter for the right eye and the liquid crystal shutter for the left eye. Then, the viewer wearing the liquid crystal shuttered spectacles 8 can alternately see the image for the right eye and the image for the left eye by viewing the display unit 9 through the liquid crystal shuttered spectacles 8. In this way, the viewer can perceive a stereoscopic image.
Thus, by the use of the infrared ray transmitting device 6, the signal line directly connecting the three-dimensional image generation unit 1 and the liquid crystal shutter control device 7 can be eliminated. Therefore, the degree of freedom as to the position of the viewer of the display unit 9 can be increased to some extent. Further, since the liquid crystal shutter control device 7 and the liquid crystal shuttered spectacles 8 are integrated into one liquid crystal shuttered spectacle device 13, viewers taking up their positions with certain degree of freedom can view the same stereoscopic image only by wearing the liquid crystal shuttered spectacle device 13.
In order to attain such a degree of freedom, non-wired signal transmission means such as an infrared ray transmitting device 6 becomes indispensable. Viewers wearing the liquid crystal shuttered spectacle device 13 are facing the display unit 9. Hence, in order that the signal receiving means in the liquid crystal shuttered spectacle devices 13 worn by the viewers accurately receive the shutter control signal, the infrared ray transmitting device 6 or the like must be disposed in the vicinity of the display unit 9.
These days, however, display units 9 designed to look nice using curved lines are prevailing. When the infrared ray transmitting device 6 or the like is disposed in the vicinity of the display unit 9, the presence of the infrared ray transmitting device 6 spoils the appearance, and the presence of the shutter control signal line 12 also spoils the appearance. Thus, there has been a problem that efforts made to design the display unit 9 to look nice become futile.